Children who develop diabetes in sub-Saharan Africa are dying within a year for want of insulin, a drug which keeps hundreds of thousands of young people well in the UK, experts are warning.

Supplies of the drug and the syringes needed for daily injections are erratic in many places in Africa and some families walk 250 miles to get the insulin their child needs.

John Yudkin, director of the international health and medical education centre at University College London, said it was shocking that children were still dying.

"If you were born with type-1 diabetes in the UK before 1920 you had six months to live; you now have 50 to 60 years," he said. "We are still in an 80-year-old scenario in sub-Saharan Africa, even though we have the knowledge in the world to keep people alive."

The International Insulin Foundation, which he heads with the project coordinator David Beran, has carried out a detailed study of the treatment available to children with type-1 diabetes in Mozambique and Zambia and concluded that better distribution of insulin and education of healthworkers, especially in rural areas, could cut the death toll.

They hope the focus on the health needs of people in the poorest countries which has come out of the global campaign for access to drugs for HIV/Aids may result in better care for those with diabetes and other diseases. "Improving the drug supply will impact not only diabetes, but all diseases," said Mr Beran.

Pressure from Aids activists has already caused the main insulin-producing drug company, Novo Nordisk, to rethink its policies towards poor states and slash insulin prices by more than half.

In the western world, daily injections of insulin and careful monitoring mean that children who develop what is known as type-1 or insulin-dependent diabetes in their early teens - the form with a genetic origin - live normal, healthy lives. Type-2 diabetes, which is usually diagnosed in middle age, is linked with obesity, but can also be stabilised.

The World Health Organisation this weekend warned that the number of people with diabetes in developing countries could more than double in 30 years, from 115 million to 284 million. About 90% of diabetes cases are type-2, but children die of type-1.

In Mozambique, a child in a rural area will live for a year with diabetes, or four years if they live in a town with a hospital. "In parts of Zambia where paediatric clinics are quite well developed, life expectancy is better, but still precarious because of problems over insulin access and the transport situation and the economic circumstances of the parents," said Mr Beran.

Susan Zimba, a paediatrician at the University Teaching Hospital in Lusaka, said access to insulin was "a deep problem. There is usually not enough to go round". When the hospital runs out, those who can afford it will buy the insulin from a private chemist, but a month's supply of two types of insulin, at £24, will cost about two-thirds of an average salary.